Battery System with Flexible Printed Circuit
Patent Information
- Authority / Receiving Office
- KR · KR
- Patent Type
- Patents
- Current Assignee / Owner
- SAMSUNG SDI CO LTD
- Filing Date
- 2020-12-22
- Publication Date
- 2026-08-03
Smart Images
Figure R1020200181065_ABST
Abstract
Description
Technology Field
[0001] An aspect of an embodiment of the present disclosure relates to a battery system having a flexible printed circuit. Background Technology
[0002] Secondary batteries differ from primary batteries, which can only convert chemical energy into electrical energy, in that they can be repeatedly charged and discharged. Low-capacity secondary batteries are used to power small electronic devices such as mobile phones, laptops, computers, and camcorders, while high-capacity secondary batteries are used for powering devices such as hybrid vehicles.
[0003] Generally, a secondary battery comprises an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes, a case housing the electrode assembly, and electrode terminals electrically connected to the electrode assembly. An electrolyte is injected into the case to enable charging and discharging of the battery through electrochemical reactions between the positive electrode, the negative electrode, and the electrolyte. The shape of the case may be manufactured, for example, cylindrical or rectangular, to suit the intended use of the battery.
[0004] A secondary battery can be used as a battery module formed from a plurality of unit cell cells connected in series and / or parallel to provide high energy density (e.g., for driving a motor in a hybrid vehicle). That is, the battery module is formed by connecting the electrode terminals of a plurality of unit cells to each other to meet the required power amount and, for example, to realize a high-output secondary battery for an electric vehicle.
[0005] The battery module may be configured in a block structure or a module structure. In a block structure, each battery cell is connected to a common current collector structure and a common battery management system. In a module structure, a submodule is formed by connecting multiple battery cells, and a battery module is formed by connecting multiple submodules. Battery management functions can be realized at least partially at the module or submodule level, thereby improving compatibility. To constitute a battery system, at least one battery module is equipped with a thermal management system, is mechanically and electrically integrated, and is configured to be connected to at least one electrical consuming device.
[0006] For the thermal control of a battery system, a thermal management system is required to ensure the safe operation of at least one battery module by efficiently heating, releasing, and / or dissipating the heat generated from the secondary batteries of the battery module. If the heat generated in the battery is not sufficiently heated, released, and / or dissipated, temperature variations will occur between battery cells, preventing one or more battery modules from generating the desired amount of power. Furthermore, if the internal temperature of the secondary battery rises, it may lead to internal abnormal reactions, which consequently degrades the charge / discharge performance of the secondary battery and shortens its lifespan. Therefore, a cooling device is required to efficiently heat, release, and / or dissipate the heat generated in the cells.
[0007] Static control methods for power output and charging alone are insufficient to dynamically meet the diverse power demands of various electrical consuming devices connected to the battery system. Therefore, it is necessary to implement continuous information transmission between the battery system and the controllers of the electrical consuming devices. This information includes important data such as the actual state of charge (SoC), potential electrical performance, charging capacity, and internal resistance of the battery system, as well as actual or predicted power demand and the surplus of the consumer. The battery system typically includes a Battery Management System (BMS) to facilitate the flow of this information.
[0008] A BMS is typically coupled to the controller of one or more electrical consuming devices as well as to each battery module of the battery system. A daisy-chain setup can be used to control multiple battery modules by a single BMS. In such a setup, the BMS can be connected in series as a master to multiple battery modules, specifically to multiple Cell Supervision Circuits (CSCs) of each battery module. Here, the BMS can be configured to receive and process information from each CSC as well as from external consuming devices or control units connected thereto (e.g., vehicle board net). Additionally, each CSC can be configured to detect the voltage and / or temperature of individual battery modules and transmit the detected voltage and / or temperature to the BMS. The CSC may also be configured for cell balancing within the battery modules.
[0009] CSCs are connected to the battery cells or busbars of each battery module to detect cell voltage and / or temperature. The connection between the CSC and the battery module can be made using wire bonds. However, applying wire bonds is a somewhat slow and cost-intensive process. For example, while flexible printed circuits can be used to establish a connection between the circuit carrier of the CSC and the battery module, the connection between the flexible printed circuit and the battery module is typically performed as a manual or semi-automatic process using additional fastening structures. Consequently, using flexible printed circuits is generally cumbersome and cost-intensive. The problem to be solved
[0010] Accordingly, the objective of the present invention is to provide a solution for connecting a flexible printed circuit to a battery system to connect a battery module and a cell monitoring circuit, while overcoming or reducing at least some of the disadvantages of the prior art. means of solving the problem
[0011] According to one embodiment of the present invention, a method for connecting a flexible printed circuit (FPC, hereinafter referred to as FPC for convenience) to a battery system is provided. The battery system includes one or more battery modules and one or more cell supervision circuits (CSC, hereinafter referred to as CSC for convenience) mounted on one or more cell supervision circuit boards (CSCB, hereinafter referred to as CSCB for convenience), for example, a corresponding number of such circuits, and generally one CSCB is provided per CSC.
[0012] A battery module comprises a plurality of aligned (or stacked) battery cells, for example, a plurality of battery cells stacked along the length of the battery module (for example, arranged adjacent to each other). The battery module may comprise a plurality of stacked prismatic battery cells. Each battery cell may comprise a cell case and a cap assembly installed on the cell case to close (for example, seal) the cell case. According to one embodiment, the plurality of battery cells each comprise an electrode assembly, a negative battery terminal, and a positive battery terminal, and one of the battery terminals may be formed, for example, as part of the cap assembly or at least connected to the cell case of the battery cell.
[0013] The CSC is mounted on the CSCB. For example, the CSCB is configured to host the CSC. Here, the CSC may be (or include) any circuit (e.g., integrated circuit) configured to receive a signal corresponding to the voltage and / or temperature of at least one battery cell of the battery module, or a microprocessor, an ASIC, or at least one battery cell of the battery module. In some embodiments, the CSC is further configured to process, analyze, and / or store the received signal, and the CSC may be configured to transmit a signal related to the received signal to another CSC and / or a battery management system (BMS). Additionally, the CSC may be configured to perform control functions for the battery module or the battery cells of the battery module. Here, the control functions may include measuring or determining cell voltage, current, resistance, or capacity, and may further include active or passive balancing of the cell voltage and / or cell current of the battery cells.
[0014] A method according to one embodiment of the present invention comprises at least the following steps. In the first step, a continuous strip-shaped FPC coil is provided. The FPC may comprise a flexible (flexible or flexible) substrate (e.g., a general flexible substrate) and may comprise (or be made of) a polyimide, polyetheretherketone (PEEK), or transparent conductive polyester film. An electrically conductive structure (e.g., an electrically conductive trace) that can be used to electrically connect nodes using the FPC is provided on or inside the flexible substrate. The conductive structure may be a planar conductive structure formed on the outer or inner surface of the FPC. Additionally, the conductive structure may be formed by surface metallization, conductive ink, etc. The conductive structure may be disposed within the substrate, for example, and may be covered by insulating substrate layers on both sides of the conductive structure. In such an embodiment, the conductive structure is locally exposed through at least one insulating layer (e.g., through an opening in at least one insulating layer).
[0015] A coil of continuous strip-type FPC can be provided through a coil holder of a tool according to one embodiment of the present invention. The coil on the coil holder can store a reservoir of FPC, and the FPC (e.g., length of the FPC) can be unwound from the coil by rotating the coil holder so that, for example, a section of the FPC extends linearly. The coil holder can be mounted on the tool head of the tool, and the tool head can be configured to perform translational motion in three dimensions.
[0016] In the next step, the first section of the FPC is unwound from the FPC coil holder, for example by the rotation of the coil holder. The tool head further includes a guide for guiding the unwound portion of the FPC. In one embodiment of the method, the unwound first section of the FPC is positioned on the first contact portion of the battery module of the battery system. Here, positioning can be performed using the tool head and / or the guide. In the next step of the method, a welded connection is formed between the conductive structure of the FPC in the first section of the FPC and the first contact portion of the battery module. The welded connection can be performed by the tool head of the tool. For example, the first section of the FPC can be automatically unwound from the coil, automatically positioned on the first contact portion of the battery module, and automatically welded to the first contact portion, for example, the conductive structure of the FPC.
[0017] In the next step of the method, the second section of the FPC is unwound from the coil and repositioned by rotating the coil holder and simultaneously moving the tool head, for example, in a translational motion. The second section of the FPC is positioned on at least one contact pad of the CSCB by the translational motion of the tool head. Then, another welded connection is formed between the conductive structure of the FPC in the second section of the FPC and the contact pad of the CSCB. In other words, all the aforementioned steps of the claimed method can be performed in a fully automatic manner, such as with the tool head.
[0018] In the final step of the present method, the first section and the second section of the FPC are separated (e.g., cut) from the continuous coil of the FPC. For example, a portion (or piece) of the FPC comprising at least the first section and the second section is cut from the continuous FPC. After cutting the first and second sections from the coil, the contact pad of the CSCB and the first contact of the battery module are electrically connected through a conductive structure of the FPC welded to the first contact of the first section and the second contact of the second section. Additionally, after cutting the first and second sections from the coil, the steps of the method can be repeated to connect the contact of the battery module (e.g., another contact) to the contact pad (e.g., another contact pad).
[0019] The method according to the embodiments of the present disclosure allows for a fully automated and flexible assembly process of flexible printed circuits in a battery production process. Additional holders used for mounting the FPC can be omitted due to the way the FPC is connected continuously to various components of the battery module. Rather, the continuous FPC coil has a long, single, and simple design that allows for rolling, welding, and automatic cutting, so it can be assembled and welded to the battery cell in a fully automated process. Thus, the present method allows for various connection designs of the FPC.
[0020] In one embodiment of the present invention, the first contact of the battery module is a battery cell terminal, a battery cell case, or a bus bar. By connecting an FPC in the first section of the FPC to the first contact of the battery module, a reliable voltage signal of the battery module can be obtained from the battery module. Individual voltage readings can be obtained by tapping the first contact of an individual battery cell.
[0021] Meanwhile, in another embodiment, the FPC is connected to a first contact and further connected to a second contact of a battery module. For example, after a welded connection is formed between a conductive structure of a first section of the FPC and a first contact of the battery module, and before a welded connection is formed between a conductive structure of a second section of the FPC and a contact pad of a CSCB, another welded connection is formed between a conductive structure of another (e.g., a third) section of the FPC and a second contact of the battery module. Additionally, the FPC may be connected to multiple second contacts of another or the same battery module of the battery system through welded connections in other sections of the FPC.
[0022] In one embodiment, the first contact may be the negative terminal of a battery cell, and the second contact may be the positive terminal of another battery cell. In this embodiment, the CSC can receive a voltage signal corresponding to the voltage of each connected battery cell of the battery module. Accordingly, a voltage signal corresponding to the entire battery module can be obtained. Additionally, the second contact is a different battery module from the first contact.
[0023] In the above-described embodiment, the first contact and the second contact are connected to a conductive structure of the FPC. For example, the first contact and the second contact are connected to the same conductive structure of the FPC through respective welded connections. Thus, a voltage signal corresponding to the entire battery module can be obtained through the conductive structure.
[0024] In another embodiment, the FPC includes a first conductive structure and a second conductive structure different from the first conductive structure. According to this embodiment, a first contact is connected to the first conductive structure and a second contact is connected to the second conductive structure. Thus, a voltage signal corresponding to an individual battery cell can be obtained through the first conductive structure and the second conductive structure, respectively. The FPC may include a plurality of conductive structures, such as an additional conductive structure (e.g., a third conductive structure) that can be connected to an additional contact of the battery module in each section (e.g., a third section) along the longitudinal extension of the FPC. For example, each battery cell of the battery module can be electrically contacted in an individual manner, such as through individual conductive structures, using a single FPC. Thus, the FPC may include a conductive structure for each battery cell of the battery module. However, the FPC may also include a conductive structure per group of cells of the battery module, for example, per group of cells tapped by a single conductive structure.
[0025] In another embodiment, a first conductive structure of the FPC is connected to a first CSCB contact pad of the CSCB, and a second conductive structure is connected to a second CSCB contact pad of the same CSCB. For example, the CSCB of this embodiment includes a plurality of contact pads, and after the step of forming a (first) welded connection between a first conductive structure in a second section of the FPC and a first contact pad of the CSCB, another (second) welded connection is formed between a second conductive structure in a second section of the FPC and a second contact pad of the CSCB. Additionally, in an embodiment where the FPC includes at least one other (third) conductive structure and the CSCB includes at least one other (third) contact pad, more welded connections may be formed between each conductive structure and a contact pad. Additionally, individual contact pads may be provided for each conductive structure. However, contact pads may be provided for a group of conductive structures of the FPC.
[0026] In a method according to one embodiment of the present invention, a CSC is placed on a CSCB and connected to a contact pad of the CSCB. For example, the CSCB may include a single CSC contact pad line for connecting an input node of the CSC to a single contact pad or to multiple contact pads for sequential measurement. Additionally, the CSCB may include multiple contact pad lines for connecting multiple input nodes of the CSC to individual contact pads for simultaneous measurement. The CSC may further include a communication pad connected to the CSC, e.g., its communication node, through a CSC communication line configured as a conductive structure on the CSCB. The CSC communication line may be separated from the CSC contact pad line. The communication line and communication node of the CSC may be connected to another CSC on another CSCB or to a BMS in a daisy-chain configuration, e.g., through the communication pad.
[0027] Another embodiment of the present invention relates to a tool for connecting an FPC to a battery module using a method according to the embodiment of the present invention described above. The tool according to this embodiment includes a tool head which may be one of a plurality of tool heads. Alternatively, the tool may include a tool head and a mount for the tool head. According to one embodiment of the present invention, the tool head includes a coil holder configured to receive a coil of a continuous strip-type FPC. The coil holder may be rotatable so that a section of the continuous coil of the FPC can be unwound from the coil by rotation of the coil holder. The tool further includes a guide configured to receive the unwound section of the FPC and to guide the unwound section of the FPC to an area parallel to the contact portion of the battery module.
[0028] Additionally, the tool head may be configured to perform translational motion, for example, in the x-direction and y-direction, in an area parallel to the contact portion of the battery module and parallel to the contact pad of the CSCB. Additionally, the tool head is configured to perform translational motion in a direction parallel to the normal vector of the contact portion of the battery module and the CSCB contact pad. The tool head may be moved by a rack and pinion drive system, a linear motor, etc. However, the three-dimensional movement of the tool head in the present invention is not limited thereto.
[0029] A tool head according to one embodiment of the present invention further includes an optical sensor for detecting the position of a unwound FPC. Additionally, the tool head may include a plurality of optical sensors for detecting the position of the unwound FPC at different dimensions. For example, a section of the FPC may be unwound from the coil of the FPC in a direction parallel to the normal vector of the contact and then deflected by a guide into an area parallel to the contact. The tool head includes an optical sensor for detecting the position (e.g., length) of the unwound FPC in a direction parallel to the normal vector. For example, a first optical sensor is used to detect the length of the unwound FPC section. Additionally, the tool head may include another optical sensor for detecting the position of the unwound FPC relative to the contact of the battery module or the CSCB contact pad. This other optical sensor may be a camera. The optical sensor may be configured to detect the position of the FPC relative to an alignment indicator.
[0030] A tool head according to one embodiment of the present invention further comprises a welder that provides a welded connection between a conductive structure of an FPC having a contact portion and a CSCB contact pad. As described above, the FPC comprises a conductive structure formed on or inside the FPC. The welded connection may be made by locally liquefying the conductive structure to form a mechanically stable and electrically conductive welded connection with the contact portion of the battery module or the contact pad of the CSCB. The welder may be an arc welder, a gas welder, or an energy beam welder (or may include). For example, the welder may be a laser configured to form a laser welded connection between the FPC and the contact portion and the CSCB contact pad (or may include).
[0031] In addition, the tool head of a tool according to one embodiment of the present invention is configured to perform rotational movement around an axis parallel to the normal direction of the contact portion of the battery module and the contact pad of the CSCB. By using the tool head according to this embodiment, the FPC may be connected to the battery module in a curved configuration according to the method of the present invention. This embodiment allows for more complex configurations, for example, connecting the FPC to multiple battery modules and CSCBs. Such configurations are possible due to the flexibility of the FPC.
[0032] Additionally, the tool head of a tool according to one embodiment of the present invention includes a cutter for separating (e.g., cutting) the FPC after forming a welded connection between a conductive structure and a CSCB contact pad. As described above, the tool head includes a guide for guiding the unwound portion of the FPC to the contact portion of the battery module or the contact pad of the CSCB. While guided by the guide, the cutter interacts with the FPC and separates the unwound portion of the FPC from the continuous portion of the FPC of the coil. The cutter includes a cutting edge mounted on the tool head and can move in the z-direction. However, the cutter may be a laser or a saw for separating the FPC.
[0033] Another embodiment of the present invention relates to a battery system comprising a plurality of battery modules, wherein the contact portion of each battery module is connected to the contact pad of a CSCB through each FPC by the method according to the above disclosure. For example, the FPC is connected to the battery module and the contact pad by performing the method according to one embodiment of the present invention described above. Additionally, the FPC may be connected to the contact portion of the battery module and the contact pad of the CSCB through the tool head of a tool according to one embodiment of the present invention as described above. Accordingly, the FPC is connected to the contact portion of the battery module and the CSCB contact pad through a welding connection.
[0034] For example, the FPC has a curved section between adjacent welded connections. Therefore, the FPC does not connect welded connections along the shortest distance between them (e.g., within the plane formed by the x and y directions), but extends in a direction perpendicular to the contacts and contact pads. For example, the curved portion of the FPC between two welded pads is curved in the height direction of the battery module. Thus, a material reservoir of the FPC is formed between the welded connections, and this material reservoir allows the FPC to compensate for spatial displacement caused by cell expansion or other factors of the battery cells forming the battery module. Therefore, the FPC provides sufficient electrical contact between the CSC and the battery cells even if cell expansion or spatial displacement of the battery cells occurs.
[0035] In a battery system according to an embodiment of the present invention, the battery modules communicate with a BMS and / or with each other. Additionally, the battery system includes a plurality of battery modules (e.g., a plurality of identical battery modules), each comprising an equal number of battery cells stacked in the same manner. Additionally, the battery system includes a plurality of identical Cell Supervision Circuit Carriers (CSCCs), each of which is connected to at least one battery module via at least one FPC. Here, each CSCC is or includes a microprocessor, an ASIC, or any suitable circuit (e.g., an integrated circuit) configured to receive a signal corresponding to the voltage and / or temperature of each battery module.
[0036] The CSCC may be further configured to process, analyze, and / or store received signals, and the CSCC may be configured to transmit signals related to the received signals to other CSCCs and / or BMSs. Additionally, the CSCC may be configured to perform control functions for at least one of the battery module or battery cell. The control functions may include measuring or determining cell voltage, cell current, cell resistance, or cell capacity, and may further include active or passive balancing of the cell voltage or cell current of the battery cell in the battery module. For example, the CSCC may comprise or be formed from a flexible circuit board (FCB), a flexible substrate commonly used in flexible printed circuits, such as polyimide, polyetheretherketone (PEEK), or a transparent conductive polyester film. Any conductive surface structure as described above, for example, a conductive line, may be printed on the substrate.
[0037] In a battery system according to one embodiment of the present invention, a first FPC is connected to the contact pads of a first battery module and a first CSCB, and a second FPC is connected to the contact pads of a second battery module and a second CSCB. For example, in this embodiment, individual FPCs are provided to connect the battery module and each CSCB to each other. For example, the FPC extends linearly between the battery module and the corresponding CSCB. This embodiment enables the use of a simple design for the FPC and tool head.
[0038] According to another embodiment of the battery system, the FPC is connected to the contact pads of a plurality of battery modules and a CSCB. For example, according to this other embodiment, a single CSC is connected to a plurality of battery modules. In this embodiment, the FPC has a curved section. For example, the FPC has a U-shape, an S-shape, or other shape with a curved cross-section. In this embodiment, the FPC is connected to the battery modules with a tool head configured to rotate about an axis parallel to the normal vector of the contact portion.
[0039] In another embodiment of the battery system, the battery system includes a first CSCB having a first communication pad and a second CSCB having a second communication pad. The first and second communication pads are interconnected via an FPC in a method according to one embodiment of the present invention as described above. For example, each CSCB includes a first communication pad and a second communication pad. According to this embodiment, the CSCs are connected to each other via an FPC and are also connected to a BMS. Additionally, the CSCs and the BMS can be connected to each other in a daisy-chain manner. A battery system having a plurality of connectable CSCBs can be configured for daisy-chain communication with a BMS. In some embodiments, the CSCs are configured to transmit and receive digital or similar signals (e.g., differential signals) via a communication pad connecting the FPC and / or the CSCs to each other and / or the BMS.
[0040] The CSCB of the battery system may be configured to host a CSC or to host each CSC. Here, the CSC may be or may include any suitable (integrated) circuit configured to receive a signal corresponding to the voltage and / or temperature of at least one battery cell of a microprocessor, ASIC, or battery module. The CSC may be further configured to process, analyze, and / or store the received signal, and the CSC may be configured to transmit a signal related to the received signal to another CSC and / or BMS. Additionally, the CSC may be configured to perform control functions for the battery module or at least one battery cell. The control functions may include measuring or determining cell voltage, cell current, cell resistance, or cell capacity, and may further include active or passive balancing of the cell voltage or cell current of the cell.
[0041] For example, each CSCB is or includes a board configured to accommodate a CSC on or inside it by providing a chip socket, landing pad, or wire frame suitable for the CSC, or at least configured to be connected to the CSC. The CSCB further includes communication lines and contact pad lines configured to establish data communication with the CSC. The communication lines can establish data communication between the CSC received on or from the CSCB and another CSC, BMS, and / or external control unit (e.g., control unit of an external consumer). Additionally, the contact pad lines are configured to read signals received by the CSCB contact pads.
[0042] Additional embodiments and features of the present disclosure are disclosed in the accompanying drawings and the following description. Effects of the invention
[0043] An embodiment of the present invention allows a flexible printed circuit to be flexibly assembled into a battery module as a fully automated process in battery manufacturing, and eliminates the need for additional components to mount the flexible printed circuit, thereby simplifying the design of the cell monitoring circuit carrier. Brief explanation of the drawing
[0044] The features will become apparent to a person skilled in the art by describing exemplary embodiments in detail with reference to the attached drawings. FIG. 1 is a schematic diagram illustrating a method for connecting a flexible printed circuit to a battery cell of a battery module according to an embodiment. FIG. 2 is a schematic plan view illustrating a battery system according to a first embodiment. Figure 3 is a detailed plan view of the battery system of Figure 2. FIG. 4 is a schematic plan view illustrating a battery system according to a second embodiment. FIG. 5 is a schematic diagram illustrating a flexible printed circuit used in an example. Specific details for implementing the invention
[0045] The following is described in detail with reference to embodiments, examples of which are illustrated in the accompanying drawings. Hereinafter, the effects and features of the present invention and the methods of implementation thereof are described with reference to the accompanying drawings. In the drawings, the same reference numerals refer to the same components, and redundant descriptions are omitted. Additionally, in the drawings, the relative sizes, layers, and areas of components may be exaggerated for clarity. However, the present invention may be embodied in various forms and should not be interpreted as being limited only to the illustrated embodiments. Rather, these embodiments are provided as examples to ensure that the present disclosure is thorough and complete, and will sufficiently convey the aspects and features of the present invention to those skilled in the art. Accordingly, processes, elements, and techniques that are unnecessary to those skilled in the art may not be described for a complete understanding of the aspects and features of the present invention.
[0046] As used herein, the term "and / or" includes any and all combinations of one or more of the related enumerated items. Additionally, when describing embodiments of the invention, the use of "able" means "one or more embodiments of the invention." In the following description of embodiments of the invention, singular terms may include plural forms unless otherwise specified in the context. Expressions such as "at least one" modify the entire list of components when preceding a list of components and do not modify individual elements of the list.
[0047] Although terms such as "first," "second," etc., are used to describe various components, it will be understood that these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The terms "substantially," "about," and similar terms used herein are used as approximations rather than degrees, and are intended to describe the inherent deviation of a measured or calculated value as perceived by a person skilled in the art. Furthermore, when the term "substantially" is used in combination with a feature that can be expressed using a numerical value, the term "substantially" indicates a range of ☐5% of the value.
[0048] FIG. 1 is a drawing illustrating a method for connecting a flexible printed circuit (20, flexible printed circuit, FPC, hereinafter referred to as FPC for convenience) to a battery cell (10) of a battery module (50) according to an embodiment. In FIG. 1, (A) is illustrated to explain the operation of a tool (70), in particular the operation of a tool head (71), in the method of the invention. In the method of the invention, a coil (25) of a continuous FPC (20) is provided to the tool head (71) of the tool (70). The tool head (71) of FIG. 1 is configured to move in all three dimensions in a translational manner as indicated by the x, y, and z arrows. As illustrated in FIG. 1, a section of the FPC (20) can be unwound from the coil (25) of the FPC (20) through two feed rolls (76). The section of the FPC (20) unwound from the coil (25) extends downward perpendicularly in the z direction within the initial tool head (71). Subsequently, a section of the FPC (20) is deflected by the rounded guide means (77) of the tool head (71) and extended to the contact area of the battery cell (10), that is, an area parallel to the upper surface of the battery cell (10). Here, the deflection is provided by the guide means (77) and the tool head (17) moving in the positive x direction. Additionally, while the FPC (20) is unwound from the coil (25), the position of the FPC (20) is determined via an optical sensor (72), for example, the FPC (20)
[0049] The tool head (71) further includes a laser (73) for welding a first section (21) of the FPC (20) that extends parallel to the upper surface of the battery cell (1), particularly the upper surface of the battery cell case (53) of the battery cell (10). In particular, the conductive structure of the FPC (20), which will be described in detail in relation to FIG. 5, is welded to the battery cell (10) by the laser (73). Thus, a welded connection (40) is formed between the first section (21) of the FPC (20) and the battery cell (10) as shown in FIG. 1(B). As further illustrated in FIG. 1(B), additional welded connections (40) are formed between other (second, third) sections (23.1, 23.2) of the FPC (20) by repeating the operation of the tool head (71) as described above in relation to FIG. 1(A). Between the welds (40), the tool head (71) performs translational motion in the x direction as well as curved motion in the z direction to form a curve between the welds (40). Furthermore, the operation of the tool head (71) is repeated in a similar manner to provide a weld (not shown) between the contact pad (not shown) of the cell monitoring circuit board (not shown) and the FPC.
[0050] The tool head (71) of the tool (70) according to the present invention includes a cutting means (74) for cutting the FPC (20) after creating a weld between a conductive structure and a cell supervision circuit board (CSCB, hereinafter referred to as CSCB for convenience) and a contact pad. As described above, the tool head (71) includes a guiding means (77) for guiding a loose section of the FPC (20) onto a contact part of the battery module (50) or a contact pad of the CSCB. The cutting means (74) interacts with the FPC (20) while the FPC (20) is guided by the guiding means (77) and separates the loose section of the FPC (20) from a continuous part of the FPC (20) in the coil (25). The cutting means (74) includes a cutting blade mounted on the tool head (71) and movable in the z-direction, but the cutting means may be a laser cutting means or a cutting saw for separation.
[0051] FIG. 2 is a schematic plan view illustrating a battery system (100) according to a first embodiment manufactured by the method of the present invention as schematically illustrated in FIG. 1. The battery system (100) includes a plurality (8) of battery modules (50). Each battery module (50) includes a plurality of stacked battery cells (not shown). The battery modules (50) are interconnected by a bus bar (54) that connects the positive terminal of one battery module (50) to the negative terminal of another battery module (50). Furthermore, the bus bar (54) is also used to provide electrical contact to the positive and negative system terminals. The 8 battery modules (50) are divided into 4 and arranged in 2 columns, and 4 CSCBs (30) are placed between the first column and the second column. Each CSCB (30) is placed between the battery module (50) of the first column and the corresponding battery module (50) of the second column and includes a cell monitoring circuit (not shown). Additionally, each battery module (50) is connected to a corresponding CSCB (30) via an FPC (20). Here, the FPC (20) is connected to the battery module (50) by a welded connection (not shown) that is automatically formed between a conductive structure (not shown) of the FPC (20) and a contact portion (51) of the battery module (50) in the first section (21) of the FPC (20) through the method of the present invention. In particular, for each CSCB (30), two battery modules (50) are connected via two FPCs (20), that is, through one linearly extended FPC (20) per battery module (50). As shown in FIG. 2, the first contact portion (51) of the battery module (50) may be positioned differently in the first section (21) of each linearly extended stripe of the FPC (20). Additionally, as shown in FIG. 2, adjacent CSCBs (30) are connected via FPC connectors (33).
[0052] FIG. 3 is a plan view illustrating the battery system (100) of FIG. 2 in more detail, particularly a plan view illustrating a section of the battery system (100) for the first battery module (50.1) and the second battery module (50.2) in the upper row (first row) of the battery module (20) illustrated in FIG. 2 in detail. With reference to FIG. 3, a first CSCB (30.1) is positioned below the first battery module (50.1), and a second CSCB (30.2) is positioned below the second battery module (50.2). In this embodiment, each battery module (50, 50.1, 50.2) includes five prismatic battery cells (10) stacked on top of each other in an arranged manner. The battery modules (50, 50.1, 50.2) may include more battery cells, such as eight or twelve battery cells. Each battery cell (10) includes a negative terminal (11) and a positive terminal (12) disposed on the upper surface of the battery cell (10). Additionally, the positive terminal (12) of the battery cell (10) is connected to the negative terminal (11) of an adjacent battery cell (10) via a bus bar (54). That is, the positive terminal (12) of one battery cell (10) in the first battery module (50.1) is connected to the negative terminal (11) of one battery cell (10) in the adjacent second battery module (50.2).
[0053] Additionally, the first battery module (50.1) is connected to the contact pad (31) of the first CSCB (30.1) via the first FPC (20.1), and the second battery module (50.2) is connected to the contact pad (31) of the second CSCB (30.2) via the second FPC (20.2). Here, each FPC (20.1, 20.2) is connected to each battery module (50.1, 50.2) at the contact portion. In particular, the first contact portion (51) of the battery module (50.1, 50.2) is a negative terminal (11) that extends laterally to provide an additional contact area for the corresponding FPC (20.1, 20.2). Additionally, the second contact portion (52) of the battery module (50.1, 50.2) is a positive terminal (12) that extends laterally to provide an additional contact area for the corresponding FPC (20.1, 20.2). In other words, a welded connection (not shown) is formed between the FPC (20.1, 20.2) and the first and second contact portions (51, 52) of the first and second battery modules (50.1, 50.2).
[0054] Additionally, a welded connection is formed between the contact pads (31) of the first and second FPCs (20.1, 20.2) and the first and second CSCBs (30.1, 30.2), respectively. Here, the welded connection is formed within the sections of the first and second FPCs (20.1, 20.2), respectively. Additionally, the contact pads (31) of the CSCBs (30.1, 30.2) are connected to each CSC (32) of each CSCB (30) via each CSC communication line (35). For example, a voltage signal from the battery module (50.1, 50.2) received via each contact pad (31) is transmitted to each CSC (32) via each CSC contact pad line (36). Additionally, each CSCB (30) includes a CSCB communication pad (34) connected to each CSC (32) via each CSC communication line (35). Additionally, the first CSC communication pad (34.1) of the first CSCB (30.1) is connected to the second CSC communication pad (34.2) of the second CSCB (30.2) via an FPC connector (33). Additionally, the FPC connector (33) is provided to connect adjacent CSCBs (30) to each other, for example, by forming a daisy-chain connection between CSCBs (30).
[0055] FIG. 4 illustrates a schematic plan view of a battery system (200) according to an embodiment. Since the battery system (200) shown in FIG. 4 is similar to the battery system (100) shown in FIG. 1, the same reference numbers are assigned to identical components and redundant descriptions are omitted. In the embodiment shown in FIG. 4, the battery modules (50) are not individually connected to the CSCB (30), but rather a group of battery modules is connected to the CSCB through a common FPC. For example, a first group of four battery modules (50.1, 50.2, 50.3, 50.4) is connected to the first CSCB (30.1) through the first FPC (20.1), and a second group of four battery modules (50.5, 50.6, 50.7, 50.8) is connected to the second CSCB (30.2) through the second FPC (20.2). Each of the first and second FPCs (20.1, 20.2) has a roughly U-shaped configuration with the opening facing downwards when viewed with reference to FIG. 4.
[0056] The first FPC (20.1) is connected to the first contact portion (51.1) of the first battery module (50.1), the first contact portion (51.2) of the second battery module (50.2), the first contact portion (51.3) of the third battery module (50.3), the first contact portion (51.2) of the fourth battery module (50.4), and the contact pad of the first CSCB (30.1). Additionally, the second FPC (20.2) is connected to the first contact portion (51.5) of the fifth battery module (50.5), the first contact portion (51.6) of the sixth battery module (50.6), the first contact portion (51.7) of the seventh battery module (50.7), the contact portion (51.8) of the eighth battery module (50.8), and the contact pad of the second CSCB (30.2). Here, the contact portion may be configured as described with respect to FIGS. 1 to 3. However, the contact portion may also be formed by the battery cell case (53) of the cell (10) or the bus bar (54) of the battery module (50).
[0057] FIG. 5 schematically illustrates an FPC (20) according to embodiments of the present disclosure. FIG. 5(A) illustrates an FPC (20) according to an embodiment having a conductive structure (24) embedded between two flexible insulating layers, and a dotted line indicates the conductive structure (24). The conductive structure (24) extends from a first section (21) of the FPC (20) to a second section (22) of the FPC (20). A first contact area (26.1) of the FPC (20) is exposed by an opening in the first section (21), and a second contact area (26.2) of the FPC (20) is exposed by an opening in the second section (22). For example, an opening in the upper insulating layer exposes the contact areas (26.1, 26.2) of the conductive structure (24) in the first and second sections (21, 22). The openings of the first and second sections (21, 22) are formed in advance in the insulating layer or during the welding process of the conductive structure (24).
[0058] FIG. 5(B) illustrates an FPC (20) according to an embodiment different from the FPC (20) illustrated in FIG. 5(A). The FPC (20) of FIG. 5(B) further includes a third contact area (26.3) of a conductive structure (24) exposed by an opening in another (e.g., third) section (23). The first and third contact areas (26.1, 26.3) are configured to contact the contact portion of the battery module, and the second contact area (26.2) is configured to contact the CSCB contact pad. The FPC (20) illustrated in FIG. 5(B) enables voltage signals of two battery cells (10) to be obtained.
[0059] FIG. 5(C) illustrates an FPC (20) according to an embodiment different from the FPC (20) illustrated in 5(A) and 5(B). The FPC (20) of FIG. 5(C) includes a first conductive structure (24.1) and a second conductive structure (24.2). The first conductive structure (24.1) includes a first contact area (26.1) exposed by an opening in a first section (21) and a second contact area (26.2) exposed by an opening in a second section (22). The FPC (20) illustrated in FIG. 5(C) enables two voltage signals of two battery cells (10) to be obtained.
[0060] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto and can be implemented with various modifications within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that such modifications also fall within the scope of the present invention. Explanation of the symbols
[0061] 10 Battery cell 11 Negative terminal 12 positive terminals 20 flexible printed circuit (FPC) 21 FPC Section 1 22 FPC Second Section 2 23 FPC Addition (Section 3) 24 FPC Conductive Structure 25 FPC coil 26 FPC contact area 30 Cell Monitoring Circuit Board (CSCB) 31 CSCB Contact Pad 32-year-old Control Circuit (CSC) 33 FPC Connector 34 CSCB communication pad 35 CSC communication line 36 CSC contact pad line 40 weld 50 Battery module 51 First contact part 52 Second contact part 53 Battery cell case 54 Busbar 70 FPC Connection Tool 71 Tool head 72 Optical sensor 73 (Laser) Welding means 74 Cutting means 75 coil holder 100,200 battery system
Claims
Claim 1 A method for connecting a flexible printed circuit to a battery module and a cell monitoring circuit board, comprising the steps of: providing a coil of a continuous and strip-shaped flexible printed circuit; unwinding a first section of the flexible printed circuit from the coil and placing the first section over a first contact portion of the battery module; welding a conductive structure of the flexible printed circuit within the first section to the first contact portion; subsequently, unwinding a second section of the flexible printed circuit from the coil and placing the second section over a contact pad of the cell monitoring circuit board; welding a conductive structure of the flexible printed circuit within the second section to the contact pad; and subsequently, separating the first section and the second section of the flexible printed circuit from the coil. Claim 2 In claim 1, the first contact portion of the battery module is a battery cell terminal, a battery cell case, or a busbar, and a connection method. Claim 3 A connection method according to claim 1, wherein the flexible printed circuit is connected to a second contact of the battery module, and the first contact is the negative terminal of the battery cell and the second contact is the positive terminal of another battery cell. Claim 4 A connection method according to paragraph 3, wherein the first contact portion and the second contact portion are connected to the conductive structure of the flexible printed circuit. Claim 5 A connection method according to paragraph 3, wherein the flexible printed circuit comprises a first conductive structure and a second conductive structure, and the first contact portion is connected to the first conductive structure and the second contact portion is connected to the second conductive structure. Claim 6 A connection method according to claim 5, wherein the first conductive structure is connected to a first cell monitoring circuit board contact pad and the second conductive structure is connected to a second cell monitoring circuit board contact pad. Claim 7 A connection method according to claim 1, wherein a cell monitoring circuit is disposed on the cell monitoring circuit board and connected to the contact pad of the cell monitoring circuit board. Claim 8 A connecting tool for connecting a flexible printed circuit to a battery module, comprising a coil holder configured to receive a coil of a continuous and strip-shaped flexible printed circuit and a tool head including an optical sensor for detecting the position of the unwound flexible printed circuit, wherein the tool head is configured to perform translational motion in an area parallel to a contact portion of the battery module and a contact pad of the cell monitoring circuit board and to perform translational motion in a direction parallel to the normal vector of the contact portion and the contact pad of the cell monitoring circuit board, wherein the tool head is configured to weld a conductive structure of the flexible printed circuit to the contact portion and the contact pad of the cell monitoring circuit board, and wherein the tool head is configured to separate the flexible printed circuit after welding the conductive structure to the contact portion and the contact pad of the cell monitoring circuit board. Claim 9 In claim 8, the tool head comprises a laser for welding the contact portion and the contact pad of the cell monitoring circuit board and the conductive structure of the flexible printed circuit, forming a connecting tool. Claim 10 A connecting tool according to claim 8, wherein the tool head is configured to perform rotational motion about an axis parallel to the normal direction of the contact portion and the contact pad. Claim 11 delete Claim 12 A battery system comprising a plurality of battery modules and a plurality of cell monitoring circuit boards, wherein the contact portion of each battery module is connected to a contact pad of one of the cell monitoring circuit boards through one of the flexible printed circuits in a manner according to any one of claims 1 to 7. Claim 13 A battery system according to claim 12, wherein a first flexible printed circuit is connected to a contact pad of a first battery module and a first cell monitoring circuit board, and a second flexible printed circuit is connected to a contact pad of a second battery module and a second cell monitoring circuit board. Claim 14 A battery system according to claim 12, wherein a flexible printed circuit is connected to contact pads of a plurality of battery modules and a cell monitoring circuit board, and the flexible printed circuit includes a curved section. Claim 15 A battery system according to claim 12, wherein the plurality of cell monitoring circuit boards comprises a first cell monitoring circuit board having a first communication pad and a second cell monitoring circuit board having a second communication pad, and the first and second communication pads are interconnected through a flexible printed circuit connector in the manner according to claim 1.